How would I go about making a mock desktop environment?

I've had an idea for a game that revolves around the user using an in-game computer for the majority of said game. It's a little experimental thing I've wanted to try... Anyway how would I do that?

I didn't really see any tutorials out there on this topic as it's kind of a niche thing. A game that looks sort of similar to what I want to do is called "Her Story".

The question is a bit too broad. You have to break it down further. What exactly is it that you are stuck at?

I once created a fake desktop using C2 (they could not show a real windows desktop for legal/copyright reasons). It was rather simple. Started with the background wallpaper, icons as sprites, and when clicked on some icons a window would pop up (also a sprite, with a drag & drop behaviour so that one could drag it around).